Fix Duplicated Translation Files in Weblate

[mariobehling]

The project currently contains duplicated translation files for some languages.
This causes problems in Weblate, where multiple files are mapped to the same language code.
Contributors may be translating the same strings in two places, leading to inconsistency and wasted effort.

Details

The following duplicates were detected:

Language	Codes	Files
Norwegian Bokmål	nb_NO, nb	lib/l10n/app_nb_NO.arb, lib/l10n/app_nb.arb
Chinese (Simplified Han script)	zh_Hans, zh	lib/l10n/app_zh_Hans.arb, lib/l10n/app_zh.arb

• First appeared: 2 weeks ago
• Last seen: yesterday

Tasks

• Identify which file should be kept as the canonical one for each affected language.
• Remove the duplicate file.
• Update Weblate configuration so only one file per language code is mapped.
• Verify that translations are preserved in the remaining file.
• Test the app to ensure localized strings are still loaded correctly.